Thermal management is often an important issue in fluid distribution systems, for example in the fuel systems of jet engines. Growing electrical generation capacity further increases the thermal loads on the aircraft. It is desirable to dump this excess heat into the fuel stream to conserve energy. The engine fuel pumping system is traditionally comprised of a boost, actuation, main, and augmenter pumps wherein the actuation pump is a variable-displacement, positive-displacement pump and the main fuel pump and the augmenter pump are high-speed centrifugal pumps.
Typically, conventional fuel systems for jet engines have had minimal to no heat capacity at high turndown conditions (i.e., low burn flow) to accommodate the increased heat loads. These conventional fuel systems, and the aircraft on which they are employed, are frequently reported to have limited operability due to thermal loads. Furthermore, the fuel pumps, which are often high-speed centrifugal pumps, may be inefficient and a significant contributor to the fuel heat load at high turndown conditions. It would therefore be desirable to have a system capable of operating at high turndown conditions with reduced fluid heat loading as compared to conventional fluid distribution systems.
Embodiments of the present invention provide such a system. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.